Effects of group size and procedural influence on consensus judgments of quantity: The examples of damage award and mock civil juries.

Davis, J. H., Hulbert, L., Au, W. T., Chen, X., & Zarnoth, P. (1997). Effects of group size and procedural influence on consensus judgments of quantity: The examples of damage award and mock civil juries. Journal of Personality and Social Psychology, 73, 703-718.

Six-person mock civil juries awarded significantly larger amounts for damages than did 12-person juries, and individuals preferred even larger average awards. A reversal of the “deep-pockets bias” observed earlier, an explanation involving temporal fluctuation in normative standards, during the time interval between the studies, was supported by independent data showing temporal trends in actual civil trial awards. A computational model of consensus that assumed a strong majority of those members with the most similar (closest) personal preferences decided on the median of their preferences accurately predicted award magnitude. Computer simulations explored the effects of critical faction size (majority, etc.) and location within the group, features that might in turn depend on task environment, cultural dynamics, and social context.

No effect of decision rule or polling format on awards; smaller juries deliberated faster and awarded larger damages. Juries with 2/3 majority rule deliberated faster than unanimity juries, especially for larger juries. Best prediction model for jury awards was median preferred value of individual jurors without considering most deviant outlier.

http://psycnet.apa.org/psycinfo/1997-06133-005